The present invention relates to a license processing apparatus, a program, and a license processing method.
Unlike analog content, digital content such as music content allows duplication a plurality of times without involving degradation of quality. For this reason, the recent rapid increase in the processing speed and storage capacity of the Internet and PCs (personal Computers) also increases the illegal distribution and exchange of content without permission by the copyright holders of the content.
In an attempt to prevent these illegal activities, a copyright management system based on the DRM (Digital Rights Management) technology intended to restrict the distribution and use of content has been gaining popularity. As proposed by SDMI (Secure Digital Music Initiative) for example, it is a general practice for the above-mentioned system to restrict the use (reproduction and copy for example) of content on the basis of use conditions written in the license (rights information) to content.
For example, Japanese Patent Laid-Open No. 2002-312211 (refer to patent document 1) discloses a copyright management system for restricting the use of content on the basis of a general license. The license to be used by this copyright management system has various content use conditions such as “time limit of use”, “time limit of download”, “permitted copy count”, “check-out count”, “CD-R recordable right”, “PD copyable right”, “right for moving to proprietary right”, and “specification logging right” for example (especially, refer to FIG. 8 of Patent Document 1). User devices such as a PC and a PD (Portable Device) evaluate these licenses by the incorporated copyright management block (a DMR module for example), thereby controlling the use of copyrighted content.
However, the above-mentioned copyright management system presents problems that the copyright management block of this system for managing the use of content on the basis of the license thereof is individually designed and mounted in accordance with the use restriction capabilities of the system and the type of a user device for example, thereby almost lacking versatility and expandability. Consequently, it is difficult to transfer copyright-managed content between user devices having different installations of copyright management blocks similar restrictions of use are imposed.
The primary role of each copyright management system is to enhance the legal portability of content in exchange for the restrictive use of content. However, with the above-mentioned related-art copyright management system, copyright-managed content may not be transferred with restriction between user devices if the installations of copyright management block thereof are different from one another, thereby limiting the enhancement of the portability of copyright-managed content. This drawback is an obstacle for the popularization of copyright management systems.
The above-mentioned problems may be attributable to the method of designing the copyright management block and the license. That is, related-art copyright management blocks are not based on module configurations suitably adapted to various content use cases such as reproduction, copy, move, rent (or check-out), return (or check-in, and storage, thereby failing to execute full use of content between a plurality of user devices. In addition, as described above, the related-art license is written with various use conditions at the same that are not written in definite categories for the above-mentioned use cases, thereby presenting a problem of poor portability. Therefore, it is difficult for the copyright management block having a specific installation to suitably determine the use conditions for evaluating each of use cases from the license corresponding to another installation.